Metallic filamentous material



March 3, 1942. F. c. JACOBS METALLIC FILAMENTOUS MATERIAL Filed Feb. 2, 1940 lNVENTO R Patented Mar. 3, 1942 l UNITED STATES TENT ()FFICE 7 2,274,699 METAL C FILAMENTOUS MATERIAL Frank 0. Jacobs, New Kensington, Pa.

Application February 2, 1940, Serial No. 316,972

4 Claims.

My invention relates to devices and articles constructed of or including elastic filaments of metal, and more particularly to the elastic filaments used in theconstruction of such devices and articles. The invention consists in an improved filament structure.

The elastic filament of the invention is particularly designed for use in packings of the construction illustrated and described in my copending application for Letters Patent, Serial No. 316,973, filed February 2, 1940, but it also is adapted for a great number of other uses. For example, the filament provides (when properly woven, knitted, or otherwise fashioned into a fabric, or a cluster or bunch) a particularly effective scouring, buffing, or abrading instrumentality, which may be used in such devices as condenser tube cleaners, metal sponges for the cleansing of cooking utensils, and the like.

In the accompanying drawing I show a fragmentary diagrammatic view of apparatus, in which the spring filament of the invention may be manufactured.

The elastic filament or filamentous spring of this invention is formed of a strand or wire of metal. The metal is a metal that, initially in relatively ductile condition, may be hardened and rendered resilient, either by cold working or by heat treatment, or by both cold working and heat treatment. familiar with many metals of this character, and it is needless herein to consider their analyses. Suffice it to say, the metal may be a brass or a bronze, or a Monel metal (a metal consisting principally of brass and nickel); alternately it may be a steel, particularly and preferably a stainless steel, or similar rustless ferrous-base metal. The selection of the particular metal to be used in the manufacture of filaments for a particular device or field of service will depend upon the conditions of service which the elastic filament must withstand, and with such matters as these the invention is not immediately concerned.

The most important aspect of the invention concerns the structural shape of the filament. It is essential that the filament will be highly flexible and resilient, and that it shall retain these characteristics over adequate periods of service. With these requisites in mind, it will be understood that the filament of the invention is, advantageously, a fiat filament of serpentine or corrugated structural form. The corrugations may consist either in a single or in a multiple system of corrugations.

The metallurgical art is I Referring to the drawing, the structure of the filamentous spring will be described.

A wire I, drawn from a supply spool 2, is first corrugated and then it is flattened in the plane of the corrugations In the courseofsuch cold working operations the initially ductile metal body .of the wire is'work hardened, and a substantial degree of resilience is imparted to such body, providing an elastic filament that embodies the, invention. (In the parlance of the art .the hardness and resilience may be said to be'induced. by cold working in the attenuated body of metal.) More specifically, the wire (in this case a round steel wire of from 008" to .030" in diameter) is led through a pair of corrugating rolls 3, 4 and is corrugated (as shown at 5), with the corrugations extending in common plane. Upon emerging from such rolls, the corrugated wire 5 is fed flat-wise between a pair of pressure rolls 6, 1, and the rolls 6, I operate to compress and spread the body of the wire into a thin elastic ribbon 8. It will be noted that the ribbonlike body of the filament extends flatin the plane of the corrugations, with the efiect that the flexibility of the filament is greatest in directions transverse to the plane of the corrugations, and the resilience or spring effect greatest in directions extending in such plane. It will be also noted that the opposite thin edges of the ribbon are presented in the crests of the corrugations, whereby the efficiency of the filament, when made into cutting, scouring, or abrading devices, is of highest order.

The pressure of the rolls 6, 7 may be regulated, such that the thickness and breadth of the body of the filament may be brought to specified values. In practice I have provided the ribbonlike filaments in thicknesses of from .001" to .010", and in breadths of from .015" to .070", but these values are merely given in exemplary way.

The corrugated elastic filament 8 will, without refinement, prove valuable in many fields of use.

However, in'some cases the resilience and hardness of its metal body may with advantage be modified, say by heat treatment, and thus brought into condition best to meet particular needs. In refinement, the corrugated filament may be further particularly constructed, to increase the characteristics desired. For example, the corrugated filament 8 may be axially twisted, in such manner that the system of corrugations do not extend in common plane, but extend in helical succession with respect to the axis of the filament. Alternately, the filament may be formed with a second system of corrugations, and it is to be noted that such a doubly corrugated filament provides the preferred or most efiective embodiment of the invention.

In the production of such doubly corrugated filament, the singly corrugated filament 8 is passed through a second pair of corrugating rolls 9, I0 and corrugated in transverse direction with respect to the plane of the first corrugations, providing the doublycorrugated filament ill. The entire filament-forming. operation may be con? ducted with continuity of operation; that is, the

filament 8 may pass in uninterrupted course from the pressure rolls 6, 1 to the second set of corrugating rolls 9, I 0, and, in the course of travel, the filament 8 may be twisted through an angle of 90, as the dotted arrows indicate in the drawing, and thus brought-intoproperposition for the second pass of corrugating rolls.-: As. is;

manifest from what has been said, the second or transverse corrugations extend .(in this .case) at an angle ofBO-"ztothe common'planelof the corrugations first formed.- Of course, in producing this doubly corrugated filament, :the ;-metal wire used will be such in character lthat the elasticity andhardness oftheafilament'. 8 will" not beso great asto prevent thesecond orfinalcorrugating and metal-workingoperations.

I claim as my invention:

1. An article of the class described consisting in a wire or'strand of resilient-metal formed-with two systems or lines of corrugationstheundulations of one system of corrugations being angu-" larly disposed with respect to the undulations of the other system.

2. An elastic filament of the sort described consisting in a thin ribbon of resilient metal cormgated or undulated in the plane of the body of the ribbon, the crests of the corrugations or undulations lying in the thin edges of the ribbon, and such filament having greatest flexibility in a direction extending transversely of thenplane in which the corrugations-lie, and having'in directions extending in such plane greatest resistance to flexure.

3. An elastic filament of the sort described con- -sisting in a thin ribbon of resilient metal corru- 

